Portable board mill

ABSTRACT

Apparatus for in-forest cutting of lumber from felled logs is provided. The apparatus comprises a frame mounting a pair of wheels around which is trained a band saw blade. A chain saw engine is releasably connected to the frame and is coupled to one of the wheels for driving the saw blade. A carriage is mounted to the frame and is adapted to extend lengthwise of the log to enable the frame to be advanced along the log as the saw blade cuts. The carriage has a series of resilient rollers which cooperate with blade guide and stabilizer assemblies to provide a straight cut. Handles are provided at opposite ends of the frame to enable workmen to mount and to dismount the apparatus and to advance the same along the log.

This application is a division of application Ser. No. 094,433, filed onNov. 15, 1979, now U.S. Pat. No. 4,276,693.

FIELD OF THE INVENTION

The present invention relates to portable board mills, and moreparticularly, the present invention relates to portable devices forcutting lumber from timber felled in the forest.

BACKGROUND OF THE INVENTION

In recent years, there has been a demand for saws capable of cuttinglumber from felled logs. Such saws are in demand because they eliminatethe need to transport logs from the forest and to a saw mill, resultingin a savings of fuel and labor. Moreover, such portable saws enablelumber to be produced in remote locations where it is intended to beused.

So-called Alaska mills have been on the market. Such mills normallyinclude attachments for standard chain saws to enable chain saws to cutboards from felled logs. Since saw chains are designed to cut transverseto the grain and not longitudinally thereof, such mills have not been asefficient as desired. Moreover, it has been difficult for even trainedoperators to cut straight boards efficiently with known Alaska mills.Also, so-called Alaska ladders must be nailed to the logs before thefirst cut is made in order to assure that a straight cut is made. Thisstep is time consuming and requires materials not always readilyavailable in remote forest locations. Furthermore, such mills tend toamplify undulations in successive cuts, and when cutting long boards, itis often necessary to drive wedges into the cut to prevent the boardfrom pinching the saw blade. Also, a substantial amount of lumber iswasted because of the relatively wide kerf of a saw chain.

Various types of portable band saws are known for cutting lumber fromfelled logs. Examples of such saws may be found in the following U.S.Pat. Nos: 3,530,908; 3,721,146; and 2,722,953. A hand-held band saw forsplitting animal carcasses is disclosed in U.S. Pat. No. 4,160,320. Oneof the patented Alaska saw mills discussed above is disclosed in U.S.Pat. No. 3,225,799. Various types of commercially available saw millsare disclosed in the June 1978 issue of Popular Science magazinebeginning at page 86.

OBJECTS OF THE INVENTION

With the foregoing in mind, a primary object of the present invention isto provide an improved portable saw mill which is capable of cuttinglumber efficiently from felled logs.

It is another object of the present invention to provide a novelportable board mill which can be utilized with conventional chain sawengines to cut straight lumber from felled logs.

A further object of the present invention is to provide a uniqueportable board mill which is capable of being used even by relativelyunskilled workmen to cut smooth, accurately dimensioned lumberexpeditiously from felled logs.

As another object, the present invention provides a portable board millwhich provides a self-correcting cutting action such that anyundulations which may be formed in one cut are automatically eliminatedin successive cuts.

Yet another object of the present invention is to provide a portableboard mill which cuts relatively straight boards from lumber withoutrequiring wedges or ancillary devices for making the first cutlengthwise of the log.

SUMMARY OF THE INVENTION

As a more specific object, the present invention provides an improvedportable lumber mill which is designed to enable two workmen to cutlumber expeditiously from a fallen log. The portable lumber millcomprises a frame which mounts a pair of wheels for rotation in spacedrelation in a vertical plane. A band saw blade is trained around thewheels. An engine is connected to one of the wheels by way of aconventional belt drive arrangement for rotating the wheels and henceadvancing the saw blade. A carriage is mounted to the frame for movementalong the top of the log. The carriage mounts a series of resilientrollers in closely spaced relation extending forwardly and rearwardly ofthe blade on opposite sides of the frame. Blade guiding and stabilizingassemblies are mounted to the frame behind the blade for guiding theblade in the zone of cutting and for engaging in the cut formed by thesaw blade to restrain pivotal movement of the frame about a horizontalaxis lengthwise of the log. The carriage is mounted to the frame in amanner which affords both vertical and tilting adjustment to enable thethickness as well as the shape of boards cut from the log to be varied.The disclosed mill enables boards to be cut with relatively flatstraight sides without requiring ancillary first cut guide devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the presentinvention should become apparent from the following description whentaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a plan view of a portable lumber mill embodying the presentinvention;

FIG. 2 is an elevational view of a portable lumber mill shown engagedwith a felled log, the view looking lengthwise of the log in thedirection of movement of the portable mill;

FIG. 3 is an enlarged fragmentary sectional view taken on line 3--3 ofFIG. 2;

FIG. 4 is an enlarged fragmentary sectional view taken on line 4--4 ofFIG. 3;

FIG. 5 is a side elevational view of the portable board mill shownadvancing rightward along a log during the first cut;

FIG. 6 is a greatly enlarged fragmentary sectional view taken on line6--6 of FIG. 5 to illustrate blade guide and stabilizing means;

FIG. 7 is an enlarged fragmentary sectional view taken on line 7--7 ofFIG. 6;

FIG. 8 is a sectional view taken on line 8--8 of FIG. 7;

FIG. 9 is an enlarged fragmentary sectional view taken on line 9--9 ofFIG. 6;

FIG. 10 is an enlarged fragmentary sectional view taken on line 10--10of FIG. 6;

FIG. 11 is a sectional view taken on line 11--11 of FIG. 10;

FIG. 12 is a fragmentary sectional view illustrating the carriage tiltedwith respect to the frame for cutting tapered boards;

FIG. 13 is an elevational view illustrating a leveling pendulum mountedto the carriage to assist workmen to level the blade while making thefirst cut; and

FIG. 14 is a fragmentary sectional view illustrating a modified shoe forsquaring logs.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring now to the drawings, FIG. 1 illustrates a portable board millM which embodies the present invention. As best seen therein, the boardmill M comprises an elongated frame F and an elongated carriage Cdisposed orthogonal thereto so that the two form a cruciform planconfiguration. An engine E is carried by the frame F and functions in amanner to be described to drive a band saw blade B which is trainedaround a pair of wheels W₁ and W₂ rotatably mounted in the frame F. Apair of blade guide and stabilizer assemblies GS₁ and GS₂ are carried bythe frame F and function in a manner to be described both to guide andstabilize the board mill M as it is advanced in the direction indicatedby the arrow while cutting boards.

The frame F comprises a pair of elongated arms 11 and 12 extending inspaced parallel relation and adapted to be disposed transversely withrespect to the lengthwise dimension of a log L to be cut. See FIG. 2. Apair of handles 13a, 14a and 13b, 14b are mounted at opposite ends ofthe frame arms 11 and 12, respectively. The handles 13a-14b enableworkmen both to lift the mill M and to guide the same as will bedescribed. A remote throttle extension TE is provided on the handle 13bto control the engine speed via a Bowden cable connected to the throttletrigger on the engine E. A pair of legs 15a, 16a and 15b, 16b are alsomounted at opposite ends of the frame arms 11 and 12, respectively. Thelegs 15a-16b function to support the mill M on the ground when it is notin use. Preferably, the frame, legs and handles are fabricated of alightweight material such as aluminum, so that the overall weight of theentire unit, including engine is less than 50-60 lbs.

The blade drive wheels W₁ and W₂ are mounted in the frame F betweenframe arms 11 and 12 to rotate in a vertical plane. To this end, eachwheel, such as the lefthand wheel W₂ is mounted for rotation on a shaft17 which extends transversely through the frame arms 11 and 12, andsuitable anti-friction bearings (not shown) are interposed between thewheel W₂ and the shaft 17. The righthand drive wheel W₁ is similarlymounted for rotation on a shaft 18 which, unlike the shaft 17, ismounted for adjustment toward and away from the shaft 17 by conventionalthreaded adjustment blocks and screws 19 and 20 connected to the framearms 11 and 12, respectively. The adjustment mechanisms 19 and 20function to enable the tension on the blade B to be set within desiredoperating limits. Preferably, each wheel, such as the righthand drivewheel W₁ has a pair of peripheral flanges 21a and 21b which function toguide the blade B as it advances around the periphery of the wheel.Furthermore, each wheel preferably has at least one peripheral groove(not shown) for accommodating the kerf of the blade B as the bladeadvances around the surface of the wheel.

In order to drive the blade B, at least one of the wheels W₁ and W₂ iscoupled to the engine E. In the illustrated embodiment, the left wheelW₂ is connected to a drive pulley 22 which is connected by drive gearbelt 23 to a smaller pulley 24. The pulley 24 is mounted on one end ofan idler shaft 25 which is supported by self-aligning pillow blocks26,26 and which is releasably connected at its other end by anadjustable collet 34 to the automatic clutch mounted on the engine E.The collet 34 enables various chain saw engines to be used to power theboard mill 10. If desired, a type of collet having internal splineswhich engage external splines on a spacer which in turn surrounds andconnects to the clutch may be used. By varying the size of the spacer,the collet can be used with clutches of various diameters.

In the disclosed embodiment, the engine E is of nominal 15 hp. ratingand runs at a normal operating speed of about 8500 rpm. With the pulley24 having a pitch diameter of about 2 in., the pulley 22 connected tothe wheel W₂ having a pitch diameter of about 10 in., and the diameterof the wheels W₁ and W₂ of about 14 in., the linear speed of the blade Bas it advances through the cutting of the zone Z (FIG. 2) is about4000-5000 ft. per min. Chain saw engines are particularly suited forthis because of their normally high speed operation.

It has been found that cutting efficiency is correlated with the numberof teeth per inch in the blade B and the horsepower of the engine E. Forinstance, with the engine E of a nominal 15 hp rating, the blade Bshould have a tooth spacing of about one tooth per two inches of bladelength to provide a satisfactory board cutting speed. With engines oflower nominal horsepower, the tooth spacing should increase, such as onetooth per four inches with a 7 hp engine. The blade should have aminimum width of 1 in. and preferably be about 11/2 in. wide to avoidany tendency to tilt as it cuts due to uneven tooth sharpness. The bladeshould also have deep gullets to remove sawdust from the cut.

For the purpose of supporting the frame F as it advances, the carriage Ccomprises an elongated rectangular strut assembly 27 which is fastenedacross the frame members 11 and 12 and which extends forwardly andrearwardly with respect to the blade B. A rectangular congruent cage 28underlies the strut assembly 27 and is connected thereto by means whichaffords vertical adjustment between the cage 28 and its mounting strutassembly 27 to enable boards of various thickness to be cut. The cage 28has a forward or leading section 28a disposed ahead of the cutting bladeB and a trailing section 28b disposed behind the cutting blade B. Eachsection of the cage 28 mounts a series of closely-spaced (almosttouching) rollers 29,29 for rotation on axles 29' along the top of thelog L, the width of the cage 28, and hence the length of each roller 29,corresponding substantially to the dimension between the innerperipheries of the wheels W₁ and W₂. The rollers extend forwardly andrearwardly of the blade B for distances at least about as great as themaximum width of the cut which can be made by the blade B.

In order to ensure a smooth cut along the length of the log L, each ofthe rollers is provided with a certain degree of resiliency orcompressibility. In the present instance, each roller 29 is fabricatedof a foamed elastomeric material, such as foam rubber, which providesboth the desired degree of compressibility and a predetermined amount offriction between the roller and the surface of the log L. As may be seenin FIG. 3, the resilience of the rollers 29 enables them to accommodateirregularities in the bark or surface of the log L by deflecting as theyroll over the irregularity. This has the effect of averaging surfaceirregularities and thus minimizing undulations of the blade as it cutsthrough the log L. As a result, a straighter cut is made, and if anexcessive irregularity is encountered, there is a tendency for the millM to self-correct in subsequent cuts so that pitching of the frame, andhence waviness of the cut is eliminated. The friction between therollers and the log L assists workmen in steering the mill 10 along thelength of the log L by restraining the tendency for the carriage to yawdue to the tendency for the blade B to displace the carriage laterallydue to reaction forces generated during cutting.

Although the roller 29 may have a constant amount of resilience alongits entire length, it is preferable for the roller 29 to be fabricatedso as to have a compressibility which varies along its length, being ata maximum at the median C_(L) of the roller 29 and at a minimum atopposite ends of the roller 29. For this purpose, it is preferable forthe roller 29 to be fabricated of a series of roller members 29a,29a(FIG. 4) each having different degrees of compressibility varying from amaximum compressibility of about RO-10 (ASTM standard D 1056-77) at theroller median C_(L) to sutstantial incompressibility adjacent oppositeends of the roller 29. By virtue of this structure, the greatercompressibility of the roller 29 centrally of the cage 28 enables themill 10 to accommodate to a greater extent the arcuate shape of the logL when the first cut is being made, while the relative incompressibilityof the roller members inwardly of the ends of the roller 29 providesfirm support for the mill 10 in all subsequent cuts because the firmerrollers are supported on the flat cut log surface adjacent its outermargins. It is noted that the axial variation in compressibility neednot be at a uniform rate and that the zones of relativeincompressibility may extend inwardly from opposite ends of the rollersfor a substantial extent.

Referring to FIGS. 1 and 5, it may be seen that the leading portion 28aof the cage 28 has a length greater than the trailing portion 28bthereof. Also, the engine E is mounted in such a manner that it overliesthe leading portion 28a of the cage 28. This construction provides theadvantage of ensuring a substantial amount of resilient roller contactwith the top of the log L, both to reduce undulations in the cut surfaceby averaging the vertical displacement of the carriage C over a greaterdistance and to provide better weight distribution for the board mill10, particularly when the mill 10 is initially placed on one end of thelog at the beginning of each cut.

In order to assist in making the initial cut in the log L, the boardmill M is provided with leveling means. In the illustrated embodiment,as best seen in FIG. 5, the leveling means includes an upstandingstanchion 30 mounted at the front end of the carriage strut assembly 27a spaced distance ahead of the engine E. As best seen in FIG. 13, thestanchion plate 30 mounts a pendulum 31 having a weighted lower end 32which swings relative to an indicator point 33b provided on thestanchion plate 30. The upper end of the pendulum 31 is connected to thestanchion plate 30 by a bolt 33a. Thus, the workmen standing on oppositesides of the log L may move the handles up and down in such a manner asto cause the lower end of the pendulum 31 to register with the indicator33b thereby insuring that the blade F is level when it is initiallyengaged with the log L and during the initial cut.

For the purpose of enhancing the cutting action of the blade B, and tostabilize the lumber mill M on the log L, the blade guide and stabilizerassemblies GS₁ and GS₂ are provided. As best seen in FIGS. 2 and 5, theguide and stabilizer assemblies GS₁ and GS₂ are disposed on oppositesides of the log L and operatively engage opposite sides of the log L ina manner to be described. Both assemblies are located on the trailingside of the frame F, and they are designed to cooperate with both theblade B and the cut L_(c) made in the log L to minimize undulations inthe cut and to help to support the blade B in the zone of cutting Zwhich has an effective extent corresponding approximately to theinterior spacing between the peripheries of the wheels W₁ and W₂. Sinceboth guide and stabilizer assemblies are of like construction, referencehereinafter will be made to the righthand assembly GS₁, it beingunderstood that the left assembly GS₂ is the same, and like referencenumerals apply.

Referring now to FIG. 6, it may be seen that the righthand guide andstabilizer assembly GS₁ comprises a platen 35 mounted at the inner endof a plunger 36 which is slidingly received inside a tube 37 disposedhorizontally adjacent the lower periphery of the wheel W₁ and connectedto the leg 16a and an inclined brace 38 connected at its upper end tothe frame member 12. The plunger 36 has a through slot 36a through whicha bolt 39 passes to limit inward and outward movement of the plunger 36relative to the tube 37. A helical compression spring 40 is interposedbetween the other or outer end of the plunger 36 and a closure member 41disposed across the outer end of the tube 37. Thus, the spring 40 biasesthe plunger 36 leftward and thereby causes the guide and stabilizerassembly GS₁ to be urged into engagement with the side of the log L suchas illustrated in FIG. 2. A handle 42 protrudes rearwardly from theplaten 35 to enable the guide and stabilizer assembly GS₁ to be movedrightward against the bias of the spring 40 when initially engaging theportable board mill 10 with the log L.

The stabilizer portion of the guide and stabilizer assembly GS₁ isdesigned to engage in the cut L_(c) made by the blade B as it advancesalong the log L to limit the pivotal motion of the frame F about ahorizontal axis disposed lengthwise of the log L, i.e., to minimizerolling of the frame F. To this end, a circular knife or a disc 43 ismounted in a recess provided in the platen 35, and the disc 43 ismounted for rotation about a vertical axis by a bolt 44. A substantialportion of the area of the disc 43 protrudes leftward from the platen 35to engage in the cut L_(c) a spaced distance behind the trailing edgeB_(t) of the blade B. In order to provide additional stability to theboard mill M, a second knife blade 45 is pivotally mounted to the platen35 behind the knife disc 43. The knife 45 has an arcuate shape andextends both inwardly and rearwardly with respect to the blade B andthereby extends a substantial distance behind the trailing edge B_(t) ofthe blade B. The second or trailing knife 45 is pivoted into an extendedposition by means of a compression spring 36 mounted in a cavity in theplaten 35. A stop 47 on the platen 35 engages the secondary knife 45 tolimit its pivotal movement relative to the platen 35. Since the knivesare normally engaged in the cut, they tend to stabilize the frame F bypreventing rolling motion of the frame as the workmen advance it alongthe log. The secondary knife 45 is of particular importance in the finalstages of cutting when the blade is approaching the end of the log andthe leading portion 28a of the cage is disengaged from the log andsupported in mid-air by the workmen. The second knife blade helps tomaintain the movement of the blade B substantially parallel with the cutduring this phase of cutting.

In order to support the blade B on opposite sides of the log L in thezone of cutting Z, and to ensure that the blade enters the wood flat,the leading side of the platen 35 is provided with a slot 35a (FIG. 9)which receives the rear margin of the blade B. The trailing edge B_(t)of the blade B is backed up by a ball or roller bearing 49 which isbolted to the platen 35 and which engages the trailing edge B_(t) of theblade B in the manner illustrated in FIG. 9. As best seen in FIGS. 6 and8, a bifurcated or slotted shoe 50 having outturned tips 50a,50a ismounted on the inside of the platen 35 for slidably engaging the surfaceof the log L.

A pair of pads 51 and 52 are mounted to the platen 35 on opposite sidesof the blade B as illustrated in FIG. 11. Since each of the pads is oflike construction to the other, reference will hereinafter be made tothe upper pad 51, it being understood that corresponding referencenumerals and description refers in like manner to the lower pad 52.

Referring now to FIG. 6, the upper pad 51 preferably has a trapezoidalshape with inclined surfaces 51' and 51". The inclined surface 51'functions when the blade is moving in the direction indicated by thearrow in FIG. 6 to deflect sawdust and other foreign matter from theblade B. The pads 51 and 52 cooperate to make certain that the blade Benters the cut flat and to prevent the blade B from vibratingexcessively in the zone of the cut.

The pad 51 is mounted for adjustment into relatively closely spacedrelation with the upper side of the blade B. To this end, a mountingblock 55 is mounted on top of the platen 35, and an eccentric 56connects the block 55 with the pad 51. As best seen in FIG. 10, theeccentric 56 has a slotted end 56a which is rotatably carried in a borein the block 55, and the eccentric has an offset end 56b which isreceived in a rubber filled cavity in the pad 51. The rubber 57 in thepad cavity functions to absorb shock between the pad 51 and the block55. The pad 51 is fastened into the eccentric end 56b of the eccentric56 by a screw 59. In order to maintain the pad 51 in properly adjustedrelation with respect to the blade B, a dog or set screw 60 is mountedin the block 55 and is adapted to be rotated into engagement with theslotted end 56a of the eccentric 56. With this structure, both the pads51 and 52 may be adjusted into closely spaced relation with the oppositesurfaces of the cutting blade B.

In certain instances it may be desirable to produce a square timber froma log L. To facilitate squaring, one of the shoes, preferably the shoeassociated with the righthand guide and stabilizer assembly GS₁ may bevertically elongated in a downward direction so as to extend asubstantial distance below and orthogonal to the plane of cutting of theblade B in a manner illustrated in FIG. 14. The shoe extension 150thereby engages the log L for a substantial distance and assists inenabling the portable board mill M to square a log L.

The portable board mill M is capable of cutting flat or tapered boardsfrom the log L. For this purpose, means is provided to mount the rollercage 28 for both straight vertical adjustment with respect to the frameF and to afford pivotal adjustment therebetween. As best seen in FIG.12, such adjustment is provided by means of a pair of rods 60 and 61calibrated in inches which are slidably received at opposite ends of thecarriage strut assembly 27. The roller cage 28 mounts a pair ofupstanding posts 64 and 65 which are normally coaxial with the rods 60and 61 when the board mill 10 is cutting parallel sided lumber. Toafford the desired tilting action, however, the lower end of each rod,such as the rod 60, has a tapered or convex terminus 60a which isreceived in a conical or concave terminus 64a of the post 64. An elastictube 66 tightly engages the rod 60 and post 64 and extends across thepoint of juncture therebetween to provide a flexible coupling whichaffords the desired tilting action in a simple yet highly effectivemanner.

To utilize the apparatus described thus far, the log L is first trimmedof branches, etc. and laid substantially horizontal. The engine E isstarted to rotate the blade wheels W₁ and W₂ for causing the blade B toadvance at the desired operating speed. Thereafter, two workmen grip thehandles 13a, 14a and 13b, 14b and place the leading end 28a of thecarriage C on the top side of the log L. Depending upon the diameter ofthe log L, the workmen may find it necessary initially to pull the guideand stabilizer assemblies GS₁ and GS₂ outwardly when they approach theend of the log before cutting. The workmen then advance the board mill10 forwardly in the direction indicated by the arrow in FIG. 5 whilesimultaneously observing the position of the pointer 32 of the pendulum31 at the front of the carriage C and working the handles up and down tomaintain the cutting blade B substantially horizontal. As the mill 10reaches the opposite end of the log L, the trailing knife 45 maintainsengagement in the cut L_(c) to prevent the workmen from tilting the mill10 and cocking the blade B. After the first cut has been made, and theslab removed, boards may be cut to any desired thickness simply byrepeating the above process.

In view of the foregoing, it should be apparent that the presentinvention provides an improved portable lumber or board mill which iscapable of efficiently producing top quality boards from felled logs inremote forest locations. The mill is relatively simple to use. It isdesigned to ensure flat cuts over long log lengths. Moreover, because ofthe narrow thickness of the blade, more lumber can be cut from a givendiameter log than would be possible with an Alaska board mill. The milldoes not require an Alaska ladder to make the first cut, andanti-pinching wedges are not needed. The board mill also cuts relativelyquickly, so that output per man hour is high.

While a preferred embodiment of the present invention has been describedin detail, various modifications, alterations and changes may be madewithout departing from the spirit and scope of the present invention asdefined in the appended claims.

We claim:
 1. In a portable mill for cutting lumber from a log, includinga frame adapted to be disposed transverse to the log, a pair of wheelsmounted for rotation in a vertical plane in said frame, a band saw bladetrained around said wheels, means for rotating at least one of saidwheels to cause the blade to form a cut in the log, and a carriagecarried by said frame to afford movement of the frame along the log asthe blade advances to cut the log lengthwise, the improvementcomprising: stabilizer means carried by said frame behind said cuttingblade in the plane thereof for engaging in the cut made by the blade torestrain motion of the frame as it advances lengthwise of the log duringcutting, said blade stabilizer means including a pair of stabilizerassemblies disposed in spaced relation on the trailing side of the frameand adapted to confront opposite sides of the log, each stabilizerassembly including knife means engaging in said cut, means mounting saidstabilizer assemblies to said frame for movement toward and away fromone another, and means cooperating with said stabilizer assemblies forbiasing them toward one another for causing their knife means to engagein said cut, whereby the knife means cooperates with the blade toprovide a substantially flat cut in the log.
 2. Apparatus according toclaim 1 wherein said knife means includes a disc disposed in the planeof the blade and means mounting said disc for rotation about a verticalaxis.
 3. Apparatus according to claim 1 wherein said knife meansincludes an arcuate blade extending inwardly and rearwardly relative tothe cutting blade, means mounting said blade for pivotal movement abouta vertical axis, and means for urging said blade inwardly for deepengagement in said cut.
 4. Apparatus according to claim 1 wherein saidstabilizer mounting means includes a tube carried by said framesubstantially tangential to the lower periphery of each wheel, a plungertelescopically received in said tube, and a platen mounted to saidplunger for carrying said stabilizer means.
 5. Apparatus according toclaim 4 wherein said biasing means includes a compression spring mountedin each tube for urging said platens toward one another, and includinghandle means extending rearwardly from each platen to afford manualurging the platens outwardly against said spring bias to facilitateinitial engagement of the apparatus with a log.